Michael, As you probably know, tin/lead/plated/fused solder termination areas "ruled" the earth before commercial SMT. It was/is the most solderable surface available - in my objective opinion. Its homogeneous surface is very nearly impervious to oxidation except under extreme conditions. You are right about coplanarity as tin/lead/plated/fused pads have a huge "hump" in the middle, but HASL is not working well in this department either - for fine pitch. If someone could come up with a tin/lead/plated/fused process, not violating environmental issues and was flat, wouldn't it be great? Earl Moon ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################